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    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
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<body>
    <h2>异步</h2>
</body>
<script>
    console.log(1)

    //宏任务
    setTimeout(() => {
        console.log(2)
    }, 0)


    //微任务
    Promise.resolve().then(() => {
        console.log(4)
    })
    console.log(3)
</script>

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